It was Jesus Christ, if Matthew is to be believed, who said, “Love thine enemy.” It is in that spirit that I write this belated valentine to Sarah Palin.

Sarah, I love you for having revealed unto the media the snarling heart of the beast that is the base (and the soul) of the Republican Party. Yes, you have the lipstick and the heels, not to mention the calves and bosoms, that send Republican men into swoons, but you have more; the pit-bull snarl that rouses your supporters to cry out, “Traitor!” against Obama, and “Kill him!”

George Bush kept those folks in their kennels, ran as a “compassionate conservative,” and always masked his most heinous plans in double speak. Bush the Elder, Ronald Reagan, and even Richard Nixon never explicitly ran on hate and fear of “the other.” They used words that were coded enough that it was possible to pretend that they were true.

But now the beast is loose.The Republican Party likes to remember Abraham Lincoln. And so they should. It’s a nice memory and brings credit to them. As does the accidental ascension of Teddy Roosevelt, environmentalist and basher of corporations. Back in the 1950s and ’60s, their party included such figures as Dwight Eisenhower—whose reputation grows ever better in retrospect—Nelson Rockefeller, who built New York’s state university system, and New York City mayor John Lindsey.

But there is another strand that runs through their history.Back in the 1840s, there was a group called the Know Nothings. They were against immigrants and for real Americans. (“Real American” did not then, as it does not now, refer to Indians, it refers to descendants of English immigrants.) The movement was based on fear. Irish and German Catholics were going to take over. They would take orders from the Pope-in-Rome (one word). Their values were not “our values.” They drank. Their nunneries were virtual brothels and when the nuns had babies they practiced infanticide.

The Know Nothings started with secret societies like the Order of the Star Spangled Banner, associated with William Poole, better known as Bill the Butcher, depicted by Daniel Day Lewis in Gangs of New York.

Their public political face was the American Republican Party, which became the Native American Party, and finally the American Party.

Their platform was:

Severe limits on immigration, especially from Catholic countries.

Restricting political office to “native-born” Americans.

Mandating a wait of 21 years before an immigrant could gain citizenship.

Restricting public school teaching to Protestants.

Mandating daily Bible readings in public schools (from the Protestant version of the Bible).

Restricting the sale of liquor.

For a brief time, the American Party was wildly popular. In 1854 party membership swelled from 50,000 to over a million in a matter of months. It elected mayors in Philadelphia, Boston, Washington, DC, San Francisco, and Chicago, and won the state legislature and governorship of Massachusetts.

But there were other things going on: the Mexican War, slavery, secession, and the Civil War. The movement didn’t last long and was soon absorbed by the Republican Party.

Fair is fair. Things morph and change. The Republican Party freed the slaves and tried to create an interracial democratic South during Reconstruction. The Democratic Party became the party of segregation in the South and the second home of the Klu Klux Klan. To be Republican is not to be necessarily narrow-minded and in dread fear of foreigners. To be Democratic is not necessarily to be liberal, progressive and open-minded.But enough of being fair.

The Great Depression demonstrated that the principles of the Republican Party were bankrupt. Like most of the country. The Democrats became the progressive party, representing social justice and programs that would protect capitalism from its own worst tendencies, moving toward a vision of a perfectable world. The Republicans became—in a very literal sense—a reactionary party, reacting against whatever the Democrats were doing, engaged in a 60-year-long war against the New Deal.

Lyndon Johnson is the pivotal figure, both heroic and deeply tragic. The Democratic Party’s dirty public secret was that its political hegemony rested on the Solid South, still refusing to vote Republican out of hatred of Lincoln. Johnson knew that if he pushed through the Civil Rights Act his party would lose the South for a generation. Or more. His heroism is that he did anyway. No, he did not end the race issue, but he broke the back of segregation.

The Republicans saw their opportunity. They pursued the Southern Strategy, wooing resentful whites with great success.

But two things happened.Racism became less and less tenable. The generation that cherished it has grown old. That pillar of the Republican Party is crumbling.

And then along came Bush-Cheney. Like Herbert Hoover, in the process of leading the country to bankruptcy they demonstrated that the Republican Party’s ideas were also bankrupt. They made government bigger, not smaller—and more intrusive, too. They didn’t oppose special interests, they were the special interests. They didn’t oppose lobbyists, they forced lobbyists to join their party at fiscal gunpoint. They were militaristic on parade, but could not run a war. They could not protect the country, nor punish the people who actually attacked us. Their policies demonstrated that free markets are a fiction, and real markets need more supervision than a grade-school playground.

Along came John McCain. He looked out, from sea to shining sea, from the mountains, to the prairies, in search of voters who would vote for him. All he could find were the new Know Nothings. People who, frightened of the way things are changing, want to change back to that white, Protestant place it was, oh, sometime back before 1840. America Firsters. Anti-immigrant. Anti-foreigner. Anti-elite. Anti-intelligence.

Not quite capable of running as a true Know Nothing himself, he chose someone who could: Sarah Palin. She does it well, and in so doing, shows us, clearly and simply, who they really are.